Constraints can be put on the data
to be plotted; they are of the form: expression relation
expression where relations are
=,!=,<,<=,>,>=. Examples are TE>3.5, I>10e3, and PGAS=2.
You can use and and or, represented by * and +
respectively, with the relational operators. For example, a
constraint of (Z=8)+(Z=9) will plot y vs x when z is
either 8 or 9. You also can use NODATA in constraints: COMMENT=NODATA, and
COMMENT="NODATA" are valid. You can use and and
or with the relational operators. Valid contraints are:
"(Z=8) OR (Z=9)"
"IP BETWEEN 1.5 and 2.5"
"IP NOT BETWEEN 1.5 and 2.5"
"COMMENT IS NULL"
"COMMENT IS NOT NULL"
Up to fifteen constraints can be used. The constraints are anded together so only records satisfying all of the conditions will be plotted.